Is him hitting on his girlfriend's other lover best friend the second he meets her skeezy?
Oh come on, now you're just digging for reasons to dislike him. I don't know what comic you're reading, but his conversations with Kory seen here aren't even flirtatious, and certainly not "hitting on". He kisses her hand in a courtly goodnight (Whilst standing next to Donna), and Kory reacts to an Earth custom she's not familiar with.
In the latter case his friends have just watched 6'10" of Kory Anders, international supermodel in short-shorts walk in. Of course they're going to be making "Homina! Homina!" noises and urgently checking their flies. Hell so would I despite my standard preferences!
And critiquing a man for the actions of the people his brother invited to his ruddy stag party??